Added semanticscholar.org as a new search engine
Added semanticscholar.org as a new search engine

Per request by Brendan

Auditors: @bbondy

Fix #5656

willy-b/browser-laptop,willy-b/browser-laptop,jonathansampson/browser-laptop,dcposch/browser-laptop,darkdh/browser-laptop,timborden/browser-laptop,dcposch/browser-laptop,darkdh/browser-laptop,luixxiul/browser-laptop,jonathansampson/browser-laptop,pmkary/braver,darkdh/browser-laptop,diasdavid/browser-laptop,pmkary/braver,pmkary/braver,luixxiul/browser-laptop,darkdh/browser-laptop,dcposch/browser-laptop,pmkary/braver,diasdavid/browser-laptop,timborden/browser-laptop,willy-b/browser-laptop,jonathansampson/browser-laptop,diasdavid/browser-laptop,timborden/browser-laptop,dcposch/browser-laptop,jonathansampson/browser-laptop,luixxiul/browser-laptop,willy-b/browser-laptop,luixxiul/browser-laptop,timborden/browser-laptop,diasdavid/browser-laptop